The exhaust of turbine powered military vehicles has become a major problem due to the large volumes of very hot air from the turbine engine. A case in point is the M1 series of Abrams tanks currently fielded by the United States Army. In its original design, the M1 tank directed exhaust gases downward through exhaust grills at the rear of the tank. These gases caused large clouds of dust to be kicked up when the tank was operated in a desert setting. Straighteners were added to the exhaust grill to direct the gases horizontally, but problems resulted when an M1 tank was used to tow another vehicle. A deflection device was then designed to be temporarily added to the straightener to deflect the gases upward whenever the M1 tank was towing another vehicle. However, this device adds undesirable extra structure to the tank exhaust outlet and must be carried with the tank when not in use. In addtion, upwardly directed exhaust gas creates an easily detectable thermal signature, which faciltates detection by unfriendly forces.
My invention is an exhaust orientation assembly that replaces the aforementioned straightener and eliminates the need for additional exhaust deflector devices. The assembly comprises a transition shroud affixed to the exhaust grill of a tank or like vehicle. A drum rotates on the shroud by means of a roller-track arrangement between the drum and shroud. Several anchoring structures mount on the shroud in equally spaced locations about the drum. The structures hold the drum in one of several angular positions relative to the shroud. Movable fins for directing exhaust flow through the drum are pivoted by a linkage. A tab on the drum can be engaged by the linkage and thereby lock the fins in a selected pivot position. Rotational force is imparted to the drum and fins by flanges obliquely attached to the fins; when exhaust gas strikes the flanges, the fins and drum spin.